Expression and activity of trypsin and pepsin during larval development of the spotted rose snapper Lutjanus guttatus
2012
Galaviz, Mario A. | García-Ortega, Armando | Gisbert, Enric | López, Lus M. | Gasca, Alejandra García
The present study aimed to describe and understand the development of the digestive system in spotted rose snapper (Lutjanus guttatus) larvae from hatching to 40days post-hatch (dph). The mouth opened between 2 and 3dph, at that moment the digestive tract was barely differentiated into the anterior and posterior intestine, although the liver and pancreas were already present. Gastric glands were observed until 20dph, followed by the differentiation of the stomach between 20 and 25dph. Trypsinogen expression and trypsin activity were detected at hatching, increasing concomitantly to larval development and the change in the type of food. Maximum levels of trypsinogen expression were observed at 25dph, when animals were fed with Artemia nauplii, and maximum trypsin activity was detected at 35dph, when larvae were fed with an artificial diet. On the other hand, pepsinogen gene expression was detected at 18dph, two days before pepsin enzymatic activity and appearance of gastric glands. Maximum pepsin activity was also observed at 35dph. These results suggest that in this species weaning could be initiated at an earlier age than is currently practiced (between 28 and 30dph), since larvae of spotted rose snapper develop a functional stomach between days 20 and 25 post-hatch.
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